DESCRIPTION: Advances in medical technology and economic pressure to reduce health care costs have converged to intensify the hourly workload of hospital interns. Yet the hospital intern's traditional 36-hour on-call shift has remained largely unaltered, recurring every 3-4 nights for months at a time, with work hours ranging from 80-110 hours/week. Laboratory and field data indicated that such extended duty shifts and long work weeks are associated with acute total sleep deprivation, chronic partial sleep deprivation, misalignment of circadian phase and sleep inertia, resulting in a deterioration of alertness and neurobehavioral performance. We plan to test the hypotheses that: 1) extended workdays/long workweeks in interns are associated with increased risk of actual and near miss motor vehicle crashes, falling asleep at the wheel, falling asleep while working, and a reduction in quality of life measures; 2) provision of 10 hours of protected time for sleep will substantially increase sleep obtained during ICU on-call nights; and 3) physicians provided with 10 hours of protected time for sleep while on-call will exhibit improved performance, enhanced alertness, and fewer microsleep episodes while on duty. A prospective questionnaire study of all U.S. physicians and dentists in their first post-graduate year is proposed to compare the occurrence of adverse events in physicians who are required to work extended work days (>30 consecutive hours) and long work weeks (>80 hours per week) versus dentists who are not required to work such extended work days or long work weeks in their first postgraduate year. A second intervention study is proposed to evaluate the efficacy of providing 10 hours of protected time for sleep in improving alertness and performance and reducing the safety hazards associated with 36-hour on-call shifts. The proposed study could have important public policy implications related to graduate medical education and training in the United States, and for the health and safety of the 100,000 medical and surgical residents who are the principal providers of medical care in academic medical centers across America.